Lifting the Material Girl's material

It was the backhanded jab heard around the world. Or at least around the celeb gossip sites. After years of mildly defending her most famous and obvious copycat, Madonna finally seemed to admit her annoyance.

"I do love her," she said of Lady Gaga at a September concert in Atlantic City. "Imitation is the highest form of flattery."

The evidence against Gaga is pretty blatant: One in three of her outlandish red-carpet outfits and stage costumes appears to come straight out of the Big M's wardrobe.

Of course, many of Lady Gaga's youngest fans may wonder: Who's Madonna?

Back in those dinosaur days when you had to use your mom's telephone (like, the kind attached to the wall!) and the only way to see music videos was on MTV (yes, actually on TV!), Madonna was ... well, pretty much what Gaga is today: an overexposed, controversy-stirring, sex-tinged pop star with some mighty catchy tunes.

She was certainly an original, though. Most modern pop divas can't say as much, at least not when they're in Madonna's company.

Twin Cities fans' 25-year wait to see the original Queen of Pop in concert finally comes to an end with concerts Saturday and Sunday at Xcel Energy Center, but we've been seeing signs of her all along. Here are her biggest imitators.

Her sexy brassieres and bodice undergarments have Madonna written all over them. Not that we're complaining. The younger starlet even wore an overt imitation of the white lace "Like a Virgin" outfit to a party in London. Some of Ri-Ri's electronic music collaborations sound M-like, too. Unlike Gaga, she's open about channeling Her Madgesty, telling MTV: "I think she reinvented her clothing style and music with success every single time." She and Madonna also paired up with famously hot-headed men in their youth, Chris Brown and Sean Penn, respectively.

There were lipstick traces of Madonna all over her "Teenage Dream" album, from the pyro-spewing bra in her "Firework" video to the title track's '80s dance-pop sound. Her summer movie "Part of Me" was clearly fashioned after Madonna's famous "Truth or Dare" documentary, down to showing Perry in post-breakup vulnerability. She cites her elder as the main inspiration behind a "darker" new album now in the works. Still, even her marriage to Russell Brand did not erase Perry's more bubblegummy image.

Another TV competition judge these days, "The Voice" coach has been humorously accused by Gaga of copping her looks. At least Xtina can claim she recycled Madonna for her own use long before Gaga did. In the 2010 video for "Not Myself Tonight," she wore a leather dominatrix outfit and drank, cat-style, from a milk bowl just as M did in her "Human Nature" and "Express Yourself" clips. On the nonmusical side, Aguilera also has tried and failed to be taken seriously as an actress.

It's hard to remember now that she's fallen far enough off the Madonna coolness scale to become a judge on "The X Factor," but there was a time when Spears was hot to have not only touched the hem of Madge's skirt -- but to also have kissed her right on the lips at the MTV Video Music Awards in 2003. She, too, wore a "Like a Virgin"-like outfit for that awards show. More recently, Brit's 2009 "Circus" tour was loaded with Madonna homages, including a top-hat-adorned outfit and sex-kitteny wardrobe changes. And on the personal front, let's not forget that they both also had children with one of their male dancers.

Madonna-wannabe rate: 7

Of course, the Fox musical TV show openly and joyously rode the Queen of Pop's coattails in its all-Madonna episode "The Power of Madonna." The comparisons go beyond that, as series creator Ryan Murphy had previously worked with M and has dropped frequent nods to her into the scripts. Also, there's the fact that the show has been a strong advocate for gay-rights issues and tolerance.